lol... thats my whole point... I think a large proportion of these fish are a bit of a mix but no one is truelly aware of this unless they give their fish a DNA test. So the issue is... we can only really trust, visually, whats before us and only those with a true understanding of what the differences are will know what these fish could be or will be seen as in the future. We can only really rely on the ideals based on the information before us.
Clearly you didn't read the various papers that were in the link that I supplied. If you had, you'd understand that one can no longer differentiate between some of the amphilophus species due to a couple of physical traits such as elongate body form or thick lips.
While the following paper no longer appears to be free, below is a link to the blog spot of one of the authors, who lives on the shoreline of Lake Apoyo.
Not a simple case A first comprehensive phylogenetic hypothesis for the Midas cichlid complex in Nicaragua (Teleostei: Cichlidae: Amphilophus)
Matthias F. Geiger, Jeffrey K. McCrary, Ulrich K. Schliewen
http://lagunadeapoyo.blogspot.ca/2012/01/sympatric-speciation-demonstrated-among.html
From that paper .........
4.3. Three species vs. multi-species concept with notes on diversity
While previous and also some recent authors distinguished between
a number of species based on morphological characters (e.g.
Elmer et al., 2010b; Meek, 1907; McKaye et al., 2002; Stauffer et al.,
2008), other authors assign numerous forms to only three species,
namely A. citrinellus, A. zaliosus and A. labiatus (Wilson et al., 2000;
Barluenga et al., 2004, 2006a; Bunje et al., 2007).
The ongoing dispute about Amphilophus taxonomy (e.g. Villa, 1976b; Stauffer et al., 2002) is certainly based on the aforementioned high phenotypic diversity within the Midas cichlid complex which sometimes hampers
ready identification in the field.
To consider this issue adequately especially when testing for alternative speciation scenarios it is necessary to stick to a conservative taxonomy and only assign taxonomically valid species names to unambiguously identifiable individuals and not to each phenotype that is similar due to only one character, i.e. elongate body form or thick lips
According to the most recent taxonomy, the Midas cichlid complex
contains nine described species at the moment, but several more
are awaiting their proper systematic treatment (McKaye et al.,
2002, Geiger et al., in preparation)."
If as you say, "we can only really rely on the ideals based on the information before us", then you need to catch up to the most current information. The information that you are relying on is based on information from 30 yrs ago, from authors such as Paul Loiselle who through no fault of his own did not understand at that time how complex this genus was.
Also, there is no evidence to support that A. labiatus and A. citrinellus will, or ever have hybridized in the wild. In captivity, yes, but not in the wild.
Here's a link to Loiselle's article;
http://www.cichlidae.com/article.php?id=106 where in 1982 he states:
To return to the problem of telling one species from the other, Table 2 presents several diagnostic features aquarists should find useful in identifying these fish. Additionally, individuals of A. citrinellus are usually deeper bodied than are comparably sized specimens of the other two species. However, this characteristic is influenced by environmental considerations and varies so markedly that it is not a reliable means of differentiating between these cichlids.
Of the four species, A. labiatus is by far the most commercially available, followed by 'C.' trimaculatum. All the A. citrinellus available to hobbyists are ultimately descended from pure stocks maintained by Barlow for research purposes. The same is true for A. zaliosum, which has been released only in small numbers. Its unattractive coloration and belligerence have apparently discouraged efforts to breed it, and I doubt the Arrow Cichlid will ever be available to hobbyists. There are too many more desirable Amphilophus available to make A. zaliosum worth a breeder's while to spawn and rear.
Even 30 yrs ago it was clear that the trait of being "deeper bodied" is influenced by environmental considerations, and varies so markedly that it is not a reliable means of differentiating between these cichlids.
Also, the original collector of amphs in the crater lakes, George Barlow (who has openly admitted this in at least one of his papers written in the 1970's) was also confused by some of these amph species, and originally viewed all of them as one species, citrinellus.
So clearly these were not all "pure stock" as Loiselle suggested.
Loiselle even mentions this in the same article, where he states:
Second, the small numbers of fish initially imported, the confusion over the number of species involved and the great eagerness to spawn them led initially to a great deal of indiscriminate hybridization.
And as trace stated, even if ones amph does have mixed genes, doesn't mean it can't be a stunning fish worthy of one keeping in an aquarium.
